Resumo - Abstract - The Science of Sound

Sound is energy created by vibration from a molecule, which causes the
other molecules nearby to vibrate as well. This energy travels trough waves, whose
characteristics determine the type of sound that is created. These characteristics are:
amplitude, that is directly proportional to the volume of the sound; and frequency,
that is related to how high or how low the sound is. Depending on the matter that the
sound is travelling trough, it can travel faster or slower. Since it is a transverse wave,
it can travel in any matter. It’s speed in air is about 1,120 feet per second. We only
hear a sound when the vibration reaches our eardrums, that vibrate as well, causing
small bones inside our ears to vibrate too, sending a message to our brain with the
characteristics of this sound. So, if nothing is around to hear the sound, it doesn’t exists.